Bandwidth adaptation makes scalable video coding an elegant solution for video streaming over Internet and wireless networks, especially since available channel bandwidth can frequently and unpredictably change in such network environments. However, wide range bandwidth adaptation also means that scalable video coding can not work efficiently at all bit-rates. For example, when a scalable video encoder is set to optimize coding performance at a low bit-rate, performance at high bit-rates is typically sacrificed. Moreover, when a video encoder is set to optimize coding performance at a high bit-rate, encoder performance at low bit rates is generally poor. Such phenomenon substantially limits the efficiency of scalable video streaming over heterogeneous networks such as the Internet. This is because the bandwidth of each sub-network can be very different.